Overviews_Exam3-1

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Chapter Overviews – Exam #3 Chapter 6 1. List the general functions of the integumentary system. Protection, thermoregulation, sensation detection, synthesis of vitamin D and excretion/ absorption 2. Draw, label and describe the structure of the epidermis. Superficial to Deep* Stratum corneum - thick layer of dead keratinocytes that protect from friction damage. Stratum lucidum - thick skin (palms/soles), large amount of keratin and thickened membranes. Stratum granulosum -lamellar granules secrete lipid rich products that act as water replant and sealant, keratohyalin converts keratin intermediate filaments into keratin. Stratum spinosum - contain intraepidermal macrophages and projections of melanocytes, held together by desmosomes, older cells generate keratin from cytoplasmic protein and start collapsing(squamous) Stratum Basale - deepest layer, continually producing new keratinocytes, bound by desmosomes, bound to basement membrane by hemidesmosomes, contain keratin intermediate filaments, melanocytes, and tactile epithelial cells. 3. Draw, label and describe the structure – and function(s) -- of the various parts of the dermis, including the accessory glands and hair follicles . Papillary region - closest to epidermis, rippled into dermal papillae (Fingers) that stabilize the epidermis and create epidermal or friction ridges where they are highest (fingerprints) makes up 20% of the dermis. Reticular region - basic structure is dense irregular connective tissue (strength and flexibility) contains bundles of thick collagen, scattered fibroblasts, macrophages, adipocytes and coarse elastic fibers are in the deepest parts. Embedded with blood vessels, nerves, glands and hair follicles. Essential to the survival of the epidermis. Epidermal ridges -increase surface area Hair- UV light protection, heat loss and debris trapping Arrector pili muscle - contraction straightens the normally ‘flat’ follicle so the shaft ‘stands up’. Hair root plexus - sensory neuron dendrites wrapped around the follicle to detected hair shaft movement. Sudoriferous glands (sweat)- Eccrine glands - thermoregulating sweat. Apocrine glands - oily secretion with pheromones Sebaceous glands (sebum)(holocrine)- associated with hair follicles, secretes a sticky, antibacterial substance for infection protection and to prevent dehydration of hair shaft and skin. Ceruminous glands - modified apocrine sweat glands in the external ear canal to protect and lubricate the tympanic membrane. Secretion mixes with dead keratinocytes and creates a waxy cerumen. Mammary glands - modified apocrine glands that produce milk

Lacrimal glands - exocrine glands in the eyes that protect them. Ciliary glands - apocrine glands found next to the base of the eyelashes and keeps eyelashes from drying out. 4. Describe the various chemicals that affect skin tone/coloration. What causes changes from “normal” for each type? a. Describe how body temperature can affect perceived skin tone. melanin is the main factor for skin tone. Melanin comes in 2 forms: eumelanin (dark) and pheomelanin (reddish). Skin tone is based on the rate and type of melanin secretion, not the number of melanocytes. UV light exposure increases production. Albinism is the inability to produce melanin. Carotene is a yellowish-orangish hydrophobic molecule that’s stored in the subcutaneous adipose tissue. (question- which came first… the carrot or carotene? :D) hemoglobin is a red color when bound to O2 or CO and can affect the redness/ color of the skin. Erythema is more blood flow (flushed, i.e. embarrassed or hot). Pallor is less blood flow so paler skin (when cold). Cyanosis is a blueish tinge when the blood is lacking o2(due to being ‘trapped’ when cold). (think of Reynaud’s) jaundice is a yellow/green coloration when bilirubin (hemoglobin breakdown product from the liver) leaks into the blood stream. 5. Identify the cutaneous glands, their secretions, and the function of that secretion. Sudoriferous glands (sweat)- Eccrine glands - thermoregulating sweat. Apocrine glands - oily secretion with pheromones Sebaceous glands (sebum)(holocrine)- associated with hair follicles, secretes a sticky, antibacterial substance for infection protection and to prevent dehydration of hair shaft and skin. Ceruminous glands - modified apocrine sweat glands in the external ear canal to protect and lubricate the tympanic membrane. Secretion mixes with dead keratinocytes and creates a waxy cerumen. Mammary glands - modified apocrine glands that produce milk. Lacrimal glands - exocrine glands in the eyes that protect them. Ciliary glands - apocrine glands found next to the base of the eyelashes and keeps eyelashes from drying out. 6. Compare and contrast the structure and growth of hair and nails (include accessory structures). Hair structure: shaft, root and bulb. Growth : matrix cells continuously for 2-8 years - .33mm a day. They stop replicating for 1-3 months, then start growing a new hair that pushes out the old. Nail structure: tightly packed, hard, dead keratinized epidermal cells with an edge, plate/ body, and root. Anchored by the hyponychium. Growth: 1 mm a week from the nail matrix in the root. 7. Compare the basics of how skin heals following a surface (epidermal) injury – such as a shallow paper cut -- vs. a deep (dermal) injury – such as burning your hand on a stove. An epidermal wound only needs migration of the keratinocytes to fill in the stratum Basale. Basal cell break contact with the basement membrane and migrate until they meet advancing

from the opposite side of the wound. (contact inhibition). Deep wound requires fibroblasts to grow back some of the dermis before the epidermis can. The new dermis does not regenerate any of the usual accessory structures, only the blood vessels. Neuron regeneration is a hit or miss. Scar tissue is formed and may loose some function. Chapter 7 & 8 1. Describe the 5 types of bones (based on shape) and give at least 2 examples of bones that fall in each category (except for the one type with only one good example ). Long bone - humerus and phalanges Short bones - carpals and cuneiforms Flat bones - sternum, pariatial bone and most of the scapula Irregular bones - vertebrae, sphenoid and part of the scapula Sesamoid bones - patella 2. Explain the differences between each of the following groups of bone structure terms: a. Foramen vs. Meatus/Canal vs. Fissure Foramen - hole through a bone Meatus- a tubular tunnel/ passage through a bone Canal- tubular/passage through a bone Fissure - slit through the bone b. Process vs. Epicondyle vs. Trochanter vs. Tuberosity Process - any bony prominence. Epicondyle - and expanded region proximal to a condyle. Trochanter - 2 massive process only on the femur. Tuberosity - rough elevated process. c. Condyle vs. Head vs. Facet/Auricular surface Condyle - rounded knob that articulates with another bone Head - the prominent expanded end of bone, sometimes rounded. Facet - smooth, flat slightly concave/vex articular surface. Articular surface - an area of bone that articulates with another. 3. Describe the functions of bone. Structural support Protection of internal organs Assistance In movement Mineral/electrolyte homeostasis Hemopoiesis Triglyceride storage 4. Draw and label the structures related to long bones

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5. Draw and label the structures related to bone histology. 6. Where is spongy bone found in the body and what is its function ? Spongey bone is found on the inside of bones. it fills the large epiphyses & metaphysis along with the space between compact bone layers in flat bones and it reinforces the inner side of the compact bone in the diaphysis. It's also the site of red blood cell formation and triglyceride storage. 7. Explain the differences between intramembranous and endochondral osteogenesis in terms of a) the type of bones formed and b) the type of template structure used to form the bone. Intramembranous - formation of flat bones, clavicle and mandible. Osteoblasts in parallel membranes secrete collagen, which later calcifies into spongy bone. The membrane eventually becomes periosteum and secrete the outer compact bone layer. Endochondral - formation of the rest of the bones. bones develop from a preexisting model composed of hyaline cartilage. Hyaline cartilage versions of bones are formed in a fetus then the cartilage is slowly replaced by osteoblasts and bone tissue. 8. Describe how the epiphyseal plate allows for growth in bone length in children. Chondroblasts in the plate replicate, secrete matrix and make a wider area of cartilage, pushing the ends of the bone away from each other. Endochondral ossification converts most of this cartilage into spongey bone. The process repeats over and over forming a larger metaphysis. 9. Describe how growth in bone width is like, or different from, growth in length. Growth in bone length happens at the epiphyseal plate with the growth of cartilage. Chondroblasts in the plate replicate, secrete matrix and make a wider area of cartilage, pushing the ends of the bone away from each other. Growth in bone width is appositional growth that forms a new matrix/lamella alongside the periosteum. Happens at the bones surface. 10. Describe “bone remodeling” and explain the various factors that affect the rate of remodeling. (Don’t forget exercise!) It is the continual cycle of osteogenesis and osteolysis, removing older/ weaker bone and replacing it with new bone. This usually happens at a set rate in adults but osteogenesis increases if bone is mechanically stressed, primarily due to the pull of muscle on bone. Mechanical stess increases bone strength by increasing deposition of mineral salts and production of collagen fibers. 11.Differentiate between the major types of bone fractures (as listed in the outline). Closed - non displaced/ simple, bone remains aligned Open - displaced/ compound, the broken parts of the bone are no longer aligned. Comminuted - area around the break is splintered.

Greenstick - one side of the bone is broken but not the other. 12.Describe the stages of bone fracture repair. How can diet help or hinder repair? Hematoma formation due to large amount of blood flow in the bone, the clot is quickly transformed into ‘granulation tissue’ due to appearance of lots of repair cells. Fibrocartilage callus formation is due to fibroblasts rapidly secreting collagen, and chondroblasts forming collagen to link broken ends tother. Boney callus formation is due to endochondral ossification forming new spongey bone. Remodeling phase is a slow replacement of the spongey bone by normal compact bone. The remolded area is usually a bit thicker than surround bone. 13. Describe the differences between primary and secondary vertebral curvatures. Primary - at birth, c-shaped due to fetal position and thoracic and sacral kyphosis. Secondary - develops in childhood, s-shaped and lordosis. Cervical lordosis developed when infant crawls and lifts head. Lumbar lordosis- developed when toddler starts walking. 14. What other things about the skeleton change as a child grows up? The cartilage skeleton develops into hard bones and the bones fuse together. 15. Describe the major differences between male and female skeletons . Estrogen helps induce formation of a shallow pelvis with a wider pelvic outlet for childbirth. Testosterone induces the formation of larger, denser bones. 16. Describe the structure of intervertebral discs and the type of stress that will rupture them Caused by the pressure on the vertebral disc when liftin heavy weight(s). nucleus pulposus protrudes through a crack in the anulus fibrosis. Occurs most often post lateral corners. 17. Describe what forms arches and why they are a good ting. 3 springy arches distribute the body weight between the heel and heads of the metatarsal bones and absorb the stress from walking.

Overviews_Exam3-1

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